Touch panels commonly incorporated in devices such as mobile telephones and personal digital assistants (PDAs) are broadly classified into display devices such as liquid crystal panels and position input devices such as touch sensors. The touch sensor includes a detection electrode formed principally in a display region, and conductive wiring disposed in a design region on the periphery of the display region. For the detection electrode, indium tin oxide (hereinafter, referred to as “ITO”) having high transparency is widely used so that visual recognizability of a display section is not hindered.
However, indium as a raw material of ITO is an expensive rare earth metal and supply thereof is unstable. Further, ITO has relatively low conductivity, and therefore has the problem that conductivity is too low for use as a detection electrode of a large touch panel that is incorporated in an electronic blackboard. In view of these situations, a replacement for ITO has been searched for and, for example, a material including a noble metal (Japanese Patent Laid-open Publication No. 2013-924) has been developed. However, use of this material in a touch panel causes light reflection specific to a noble metal and associated visibility of a detection electrode, leading to deterioration of visual recognizability of a display section.
Further, there has been the problem that ITO formed in a display region of a touch sensor and conductive wiring disposed in a design region on the periphery of the display region have poor connectivity ascribable to poor adhesion between ITO and a material used in conductive wiring, and a position shift resulting from thermal shrinkage, a chemical solution residual on the surface and physical stimulation due to involvement of various steps such as a heating step and a step of laminating other materials, between a step of forming a pattern of ITO and a step of forming conductive wiring disposed in the design region, and thus failures such as disconnection and poor conduction frequently occur. Accordingly, an entirely novel technique of replacement for ITO has been strongly desired.
Thus, it could be helpful to provide a touch sensor member on which a detection electrode (minute conductive pattern) which functions as a replacement for ITO, causes no problem pertaining to visibility of the detection electrode and light reflection in the display region, inhibits disconnection and poor conduction between the detection electrode and conductive wiring (conductive pattern) in a design region and has excellent conductivity, is formed in the display region. It could also be helpful to provide a method of producing the aforementioned touch sensor member.